On Sunday, July 21, Joe Biden became a lame-duck president. On Monday, President Biden traveled to Austin, Texas, to speak at the Lyndon Johnson Presidential Library, to commemorate the anniversary of the Civil Rights Act of 1964. That library honors the last U.S. president to withdraw from his campaign, and Biden’s visit there marks the start of his effort to shape his legacy.

On Sunday, July 21, Joe Biden became a lame-duck president. On Monday, President Biden traveled to Austin, Texas, to speak at the Lyndon Johnson Presidential Library, to commemorate the anniversary of the Civil Rights Act of 1964. That library honors the last U.S. president to withdraw from his campaign, and Biden’s visit there marks the start of his effort to shape his legacy.

Biden’s lame duck period comes earlier than most. Freed from the constraints of running for reelection, the president will propose bold reforms to the Supreme Court, including term limits for justices and an ethics code. He also plans to push for a constitutional amendment to limit immunity from criminal prosecution for presidents.

But Biden will not have the benefit of a second term. And unlike most one-term presidents, he won’t even have the months leading up to the election during which his political capital could be deployed at full strength. Instead, like Presidents Lyndon Johnson in 1968 and Harry Truman in 1952, Biden enters the final summer months with everyone sure of one thing—come January 2025, he will no longer be the most powerful person in the United States.

What Can Biden Get Done Now?

Historically, lame-duck presidents have experienced mixed success, and over the course of the twentieth century, the time to be a lame duck diminished. The 20th Amendment, ratified in 1933, shortened the transition period from March to January. But even with a limited time span, some presidents have capitalized on the period, especially as their approval ratings often rise.

There are lame-duck experiences that can offer Biden inspiration. Under the lame duck period’s most expansive definition—meaning the final year of a second term—some in the Oval Office have achieved big goals. President Theodore Roosevelt in 1908 moved on a number of major conservation initiatives and started the Great White Fleet. Fast forward to 2008: President George W. Bush, at the height of his political unpopularity, pushed through Congress the Troubled Asset Relief Program in response to the financial crisis. He did so over the opposition of hard-line conservatives in his own party.

Taking a more traditional definition of the lame-duck period, focusing on the weeks between a failed reelection bid or the election of a successor in November and the inauguration, there are presidents who have experienced last-minute success. In December 1980, President Jimmy Carter signed into law the Alaska National Interest Lands Conservation Act that protected more than 150,000 acres of land. Though the public did not see his progress, Carter also negotiated an end to the Iran hostage crisis—trying to humiliate him, the Iranians refused to release their hostages until after Ronald Reagan was sworn into office. In December 2000, President Bill Clinton signed the Everglades Restoration Act, that provided $7.8 billion to restore the Florida Everglades. He also secured $1.2 billion in emergency school repairs.

Besides legislation, executive power has often been a tool of choice. In December 2000, Clinton established the largest nature preserve in the history of the United States through an executive order designating the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve. Sixteen years later, President Barack Obama issued an executive order ramping up U.S. efforts to deal with malicious cyber activity undermining the democratic process.

A few presidents have also been able to secure judicial nominations as their presidency ends. Just nine days after losing the 1980 election to Reagan, Carter nominated Stephen Breyer to the First Circuit.

But the lame-duck period has also been one of immense frustration, where presidents desperately try to complete unfinished business only to run headfirst into the same forces that had stifled their progress in previous years. Moreover, when domestic and foreign opponents feel comfortable that they are dealing with someone who very soon won’t have much sway over them, the incentives to cooperate diminish. In some cases, adversaries, particularly those overseas, might be more motivated to take aggressive action based on the sense that the commander-in-chief is vulnerable.

Lame duck inaction has often produced calamitous long-term effects. In December 1860 and January 1861, President James Buchanan refused to act forcefully in response to six southern states seceding from the union. Civil War ensued. President Benjamin Harrison would not take action in 1888 and 1889 as investors pulled their money out of the stock market for fear of Democratic policies that were to come under Grover Cleveland. The result was a financial crisis. Following the election of Franklin Roosevelt in 1932, the outgoing president Herbert Hoover refused to sign legislation sent to him by a Democratic Congress dealing with pressing matters connected to the Great Depression, including the imploding banking and farming sectors.

Then there are major pushes that fall flat. Most famously Johnson, who hoped that he could broker a deal to end the Vietnam War after he had stepped out of the race, failed to achieve his goal. Tensions among the different actors in Southeast Asia, domestic political pressures, as well as illicit actions by allies of Republican candidate Richard Nixon subverted negotiations. Negotiations that Clinton undertook with Israeli Prime Minister Ehud Barak and the Palestine Liberation Organization’s Yasser Arafat in late December 2000 at Camp David did not culminate in a durable agreement.

Sometimes the lame duck period pushes presidents into following their worst instincts rather than their better angels. On Dec. 24, 1992, President George H.W. Bush undermined his reputation by pardoning six of the people who had been indicted in the Iran-Contra scandal. His successor ended his second term by pardoning Marc Rich, a donor who had been convicted of tax fraud. President Donald Trump of course beats Bush on this, as he spent much of his lame duck period attempting to overturn the results of the 2020 election, culminating in the mob attack on Congress on Jan, 6, 2021.

Freedom from electoral concerns can also result in taking actions overseas which become extremely problematic for the next person in the Oval Office. George H.W. Bush sent 30,000 troops into Somalia, turning into one of Clinton’s biggest calamities when 18 soldiers were killed in October 1993.

Certainly, Biden won’t have it easy in the months ahead. His political opposition on Capitol Hill will only intensify as Republicans aim to connect his administration to Vice President Kamala Harris. Congressional Republicans who are beholden to their nominee will feel intense pressure to follow the party line. None of them will be in any mood to help Biden score major victories that would strengthen his legacy and Harris’s campaign. The Supreme Court reforms will not receive the two-thirds majority they need in the Senate and they would certainly not make it through the ratification process.

Nor are any of the major foreign policy problems he has struggled with going to get easier. While the prospects for a cease-fire agreement between the Israelis and Hamas have improved in recent weeks, primarily because the military operations are drawing to a close, tensions in the Middle East might be getting much worse, particularly after the successful rocket attacks against Israel by Hezbollah in the North. Although the Middle East remains Biden’s best opportunity to achieve a diplomatic breakthrough, especially with an agreement with Saudi Arabia, the problems remain severe. There is also little indication that ending the war in Ukraine is possible any time soon.

The reality is that Biden’s best chance to shore up his legacy will not be anything that he does or does not do in his remaining months. The most important factor will be the results of the presidential and congressional elections.

Nothing would be more devastating to how Biden goes down in the history books than a victory by Trump. Not only would such an outcome constitute a repudiation of what the president has accomplished in terms of his policy record and his governing style, but Biden would be blamed for having stifled any primary challenges and having waited too long to step down. Moreover, based on potential plans outlined in documents such as Project 2025, much of a second Trump term would be devoted to reversing what Biden has built.

However, a victory by Harris, as well as a possible Democratic Congress, would enshrine Biden’s decision to withdraw from the race as a historic move that saved the party, and in the minds of Democrats the nation. A Democratic victory would also ensure that there would be a successor who would build on, and strengthen, the politics that the administration has put onto the books. A successful election for Democrats will offer the best chance for Biden to avoid experiencing what happened to Obama in 2016, when Trump brought his wrecking ball to Washington and moved to wipe away the hope that the two-term leader had brought to the nation.

By Julian E. Zelizer, a professor of history and public affairs at Princeton University.